And I'm Linda Wertheimer. Osama bin Laden's son-in-law has pleaded not guilty in New York federal court this morning. He's been charged with conspiracy to kill Americans. He was captured in Jordan last week. What is interesting about this terrorism case is that it is not being heard in the military commissions at Guantanamo Bay. It is in a U.S. criminal court. Now that bin Laden's son-in-law is on trial in New York, he will be one of the people with the closest connection to the terrorist leader to ever face charges in a U.S. court.

NPR's Dina Temple-Raston is here with details.

So, Dina, bin Laden's son is in custody. Tell us about what happened this morning. Tell us about the charges.

DINA TEMPLE-RASTON, BYLINE: Well, he pleaded not guilty to conspiracy. The Justice Department had unsealed his indictment last night, and just said that there was one charge, this conspiracy to kill Americans. Now, we know that Sulaiman Abu Ghaith, the son-in-law, was a spokesman for al-Qaida. He appeared in al-Qaida's videos. He was sitting right next to his father-in-law, bin Laden, when he took credit for the 9/11 attacks the day after they happened.

So, basically, he's facing a charge for helping al-Qaida and being part of its overall terrorist conspiracy. And we don't know if there are other charges that are still under seal, but for now, he has answered this one charge: conspiracy to kill Americans.

WERTHEIMER: And he pleaded not guilty.

TEMPLE-RASTON: And he pleaded not guilty.

WERTHEIMER: So that's happening in federal court, in New York. Why is he not being tried at Guantanamo?

TEMPLE-RASTON: Well, that's a great question, because certainly on the surface, he appears to be the perfect candidate for military commissions. He's a foreigner. He has ties to al-Qaida. In fact, Republicans came out overnight and criticized the decision to try him in a civilian court.

But if bin Laden's son-in-law is charged with conspiracy, that just about rule out the tribunal down at Guantanamo, because conspiracy is considered an idiosyncratic, American-style offense. International law doesn't recognize it as a war crime, and the commissions are supposed to be all about war crimes.

WERTHEIMER: Dina, how did the U.S. find this guy and capture him?

TEMPLE-RASTON: Well, for the past 10 years or so, Abu Ghaith has been hiding out in Iran. And it's a bit of an open secret that a whole bunch of al-Qaida figures and their families escaped to Iran after the 9/11 attacks. In fact, his stay in Iran is actually mentioned in the indictment. And the al-Qaida people who are there are on a kind of catch-and-release program. It depends on the whims of the Iranian government.

Sometimes they can travel. Sometimes they're under house arrest. And, apparently, last month was a time when they were allowed to travel, because bin Laden's son-in-law left Iran and went to Turkey under a false passport. And when Turkish officials were made aware of that, they went to the luxury hotel where he was staying in Ankara, and they arrested him. And then they held him briefly and then decided, since he hadn't committed any crime on Turkish soil, they had nothing to charge him with. So they deported him.

WERTHEIMER: Where did they send him? Back to Iran?

TEMPLE-RASTON: No. Actually, he's a Kuwaiti national. But his citizenship was stripped after the 9/11 attacks. So he's essentially stateless. So the Turks sent him back to Kuwait via Jordan, and it's in Jordan where the U.S. apparently picked him up.

WERTHEIMER: And that's how he came to New York?

TEMPLE-RASTON: Exactly. Once a determination was made that he would face charges in a criminal court, he was brought to New York. This morning, he appeared the southern district of New York, which has a tremendous amount of experience in trying terrorism cases. And the judge in the case is Judge Lewis Kaplan, who was the judge in the African embassy bombings case. Now the big question now is whether Abu Ghaith is cooperating. And you can imagine that he has a lot of information about other al-Qaida people who are in Iran, and that would be very helpful to the U.S. But it's unclear whether or not he's talking.